Abstract: An improved device for athletic exercise by pulling at a resisting force. The device consists of a number of spring housing assemblies that are stacked and clamped in a column with at least one pulley wheel assembly to which a cord and pull handle is attached. A grooved metal shaft is disposed throughout the column longitudinal axis to drive all the constant-force spring assemblies which are stacked inside the device when the pulley wheel is caused to rotate. A person uses the device by first selecting which spring assemblies he wants to produce a particular resisting force level, by pushing separate selector levers, one for each spring. He then pulls at the pull handle to experience the chosen resisting force. The device design allows a user the choice of many resisting force levels, using only a small number of spring assemblies. The device is small, light in weight and conveniently shaped for easy attachment to any suitable restraining object.

Abstract: A device for athletic exercise by pulling at a resisting force. The device consists of a small cylindrical enclosure containing a number of constant force, circular wound spring assemblies, having a pulley molded to the enclosure, and having a force selector assembly connected to the enclosure which also serves to hold the device in any fixed location. A cord is wound around the pulley during assembly and its free end is attached to a pull-handle. A person uses the force selector by manually moving a spring-loaded adjustment knob through slots in the selector assembly to a slot which corresponds to the desired force level. This action causes a spring-engagement rod inside the selector assembly to engage the number of spring assemblies that will produce the selected resisting force when a person pulls at the pull handle. The device is small and light in weight. Provision is made for attachment of the device to any suitable restraining object or static equipment.